This invention relates generally to implantable electrical leads and their connector systems, and more particularly relates to connector systems for multiple conductor electrical leads used in conjunction with cardiac pacemakers.
Early implantable electrical leads having multiple conductors tended to have an individual connector pin coupled to each conductor in the electrical lead, and a connector block having a lumen corresponding to each connector pin mounted to the implantable stimulator. Examples of such connector systems are illustrated in U.S. Pat. No. 3,348,548, issued to Chardack, and U.S. Pat. No. 4,144,891, issued to Lysfjord et al. More recently, there has been a trend toward in-line connector systems, which employ a single connector pin having linearly arranged conductive surfaces, mounted to the electrical lead and a connector block having a single lumen containing correspondingly arranged connector surfaces. Such systems are illustrated in EPO Patent No. 0 052 879, issued to Rose, U.S. Pat. No. 4,572,605, issued to Hess, and U.S. Pat. No. 4,603,696, issued to Cross et al. A variety of methods for maintaining electrical contact in such systems have been employed. These include set screws, as illustrated in U.S. Pat. No. 3,908,668, issued to Bolduc, spring members, as illustrated in U.S. Pat. No. 4,445,511 issued to Cowdery et al, collets, as illustrated in U.S. Pat. No. 4,278,093, issued to Lafortune et al, and garter springs or conductive polymer rings as illustrated in U.S. Pat. No. 4,437,474, issued to Peers-Trevarton. A variety of methods of maintaining the physical interconnection of the connector system have also been employed. These include the above-mentioned methods for maintaining electrical contact, and also include bayonet type fittings used on early G.E. pacemakers and locking mechanisms, as illustrated in U.S. Pat. No. 4,540,236, issued to Peers-Trevarton.